The Cell Culture Core is established as a resource for all projects in the center. The Core provides several services to the individual projects: 1) It provides primary cell cultures, including CF epithelial cells, to participating investigators. 2) It provides cell lines for studies of the expression of recombinant CFTR. 3) It develops new culture conditions and substrates that allow the most efficient use of cells and provide the optimal conditions for individual investigators. 40 It provides investigators with recombinant vaccinia virus stocks. 5) It maintains hybridomas producing monoclonal antibodies and provides the antibodies to individual investigators.